Fluid-operated motor



0. E.- CLARK. FLUID OPERATED MOTOR. APPLICATION" FILED MAR. 25; I918.

I' Q-M IGI PaIIenIeII-Aug; II, I922.

affozneq OMAR E. CLARK, OF DENVER, COLORADO, ASSIGNOR TO THE DENVER ROCK. DRILL MANUFACTURING COMPANY, 03 DENVER, COLORADO, A. COLBJPORATIQN 011 DELAWARE.

FLUID-OPERATED MOTOR.

Application filed March 26, 1918.

To all whom it may concern:

lie it known that l, OMAR E. CLARK, a citizen ol the United States, residing at Denver, in the county of Denver and State of Colorado, have invented certain new and useful Improvements in Fluid-Operated Motors, of which the following is a specification.

The present invention relates to so-called pneumatic tools or motors of the type operated by expansive fluid under pressure, and

one of the primary objects is to provide an apparatus of this type in which the piston will be more effectively cushioned, especially upon its rear stroke, thereby eliminating the excessive recoil which is undesirable and unsuit-able under practically I all conditions. Incidentally a further advantage is to provide a tool in which the motive fluid is successively delivered to different portions of the piston, thereby adding gradually increased-power to the blow, and also reducing the recoil.

The preferred embodiment of the invention is illustrated .in the accompanying drawing, in which Figure 1 is a longitudinal sectional view through a tool designed especially for rock drilling purposes. Figure 2 is a view similar to Figure 1, but illustrating the piston at the rear end of its stroke.

A cylinder member is employed, comprising a barrel 1, having a reduced portion constituting a front head 2 enclosed at its rear end by a head 3. A piston chamber l of relatively great diameter is "formed in the barrel, and the head 3 has a chamber 5 opening into the chamber and 0t less diameter. than said chamber 1:. A piston of the hammer type employed, comprising ahead 6 with oppositely extending neck ortions 7 that are equal in size and shape, so that the piston can be reversed and either end utilized for delivering the blow. The head 6 operates in the chamber 4t, and one of the necks 7 reciprocates in the chamber Motive fluid is supplied to the tool through a rotary throttle valve 8, having a bore 9 in communication with any suitable source, and provided with a lateral port 10 that is movable into and out of communication with a supply passageway 11. This passageway has lateral ports 12 and 13, opening respectively in advance and in rear of the chamber 4:, the port 12 communicat- Specifieation of Letters Patent.

Patented Aug. 1, 1922.

Serial No. 224,742.

ing with an annular groove 14 formed in the chamber 5 contiguous to its juncture with the chamber 4;. The necks? oi the piston have reduced portions 15, which alternately afford communication between the ports 12 and 13 and the chamber l on op posite sides of the head 6. Said head also operates across suitable exhaust-permitting means 16, will be readily understood.

There is also providedv a passageway 17 extending from. the rear end of the piston chamber 1, and opening into the chamber 5 between the port 12 and the outer end of said chamber, as shown at 18. Just in rear of said port 1.8 the walls of the chamber 5 are provided with an annular rib 19 that snugly receives the neck 7 of the piston when said neck crosses the port 18.

/Vith the elements'as shown in Figure 1, it will be evident that motive fluid supplied to the passageway will pass through the port 18, and traversing the frontgroove 15, will enter the piston chamber 1 in advance of the head 6, thereby operating against said head and driving the piston rearwardly, the exhaust in rear of the same taking place through the exhaust channel 16. When the parts are in the position shown in Figure 1, it will be noted that the port 12 is entirely out ofi from the chamber 4;, as the rear groove leis entirely in ad- Vance of said port. When the rear end or the neck 7 crosses the port 18, it will enter the annular rib 19, and having a snug fit therein, will trap. motive fluid, thereby pro ducing a cushion on the small end of the piston. This causes a more gradual stop of the hammer and a resultant rebound, which will contribute to higher efficiency. This will be evident when itis considered that the cushion chamber in rear of the rib 19 is relatively small in diameter and also relatively deep, thus providing greater resiliency and spring to the cushion. When the hammer is in its rearmost position as shown in Figure 2, the groove 15 in the rear neck will afford communication betweenthe port 12 and the piston chamber ,4 in rear of the head 6. Consequently motive fluid will operate against the rear face of the head, nd added to the resiliency of the cushion produced, will drive the piston forwardly. The head 6 having crossed the channel 16, the exhaust will now take place from the chamber a in advance of said head 6-. AS

Mil

soon as therear end of the neck 7 passes the annular rib 19, motive fluid will pass through the channels 17 and operate against the rear end of the neck 7, thus adding to the force of the blow delivered.

From the foregoing, it is thought that the construction, operation and many advantages of the herein described invention will be apparent to those skilled in the art, without further description, and it will be understood that various changes in the size, shape, proportion and minor details of construction, may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus fully described my invention,

what I claim as new, and desire to secure by Letters Patent, is

1. In a tool of the character set forth, the combination with a cylinder member having piston chambers of differentdiameters, of a piston having portions of different diameters faced in the same direction and respectively operating in the chambers, means formed inthe cylinder member for delivering motive fluid first to the larger piston chamber, meansin the cylinder member controlled by a portion of the piston for afterwards delivering motive fluid to the smaller portion of the piston, means for permitting the fluid to escape from both chambersto a point-outside the cylinder member, and other means directing motive fluid against an opposing portion of the piston to move'the piston in an opposite direction.

2.111 a tool of the character set forth, the combination with a cylinderimember having piston chambers of different diameters, of a piston having portions of different diameters faced in the same direction and respectively operating in the chambers, means formed in the cylinder member for delivering motive fluid first to the larger of said chambers and against the portion of the piston operating therein,'a passageway formed in the cylinder member and opening into both the larger'and the smaller piston chambers for supplying motive fluid from the larger to said smaller chamber, the outlet of said passageway being controlled by the smaller portion of the piston operating in said smaller chamber, said larger chamber having an exhaust port for both chambers opening outside the cylinder memberand controlled by the portion of larger 7 diameter, and meanscontrolled by the piston for supplying live fluid against an opposite face of the covered.

3. In a tool of the character set forth, the combination with a cylinder member having piston chambers of diflerent'diameters, of a piston having portions of diiferent diameters faced in the same direction and respectively operating in the'chambers, a passagepiston when said exhaust is un way formed in the cylinder member for delivering motive fluid to the larger of said chambers and against the portion of the piston operating therein, a passageway for fluid formed in the cylinder member between the larger and smaller chambers and opening into the larger chamber independently of the smaller chamber, the rear end only of said latter passageway being covered and uncovered by the smaller portion of the piston to control the passage of fluid therethrough, and said smaller portion of the piston also controlling the first mentioned passageway.

i. In a tool of the character set forth, the combination with a cylinder member having piston chambers of different diameters, of a piston operating in the piston chamber and having portions of different diameters faced in the same direction and operating respectively in the chambers, a supply passageway opening into the smaller chamber contiguous to the larger chamber, a passageway opening into the large chamber at one side of and independently of the smaller chamber, said passageway also opening into the small chamber in rear of the first passageway, means formed in the piston for affording communication between the first passageway and the larger chamber, the smaller portion of the piston operating across the end of the second passageway that opens 1 into the smaller chamber and alternately closing and opening the same.

5. In a tool of the character set forth, the combination with a cylinder member having piston chambers of different diameters, of a piston having portions of different diameters respectively operating in the chambers, means for supplying motive fluid to both chambers and against the portions of the pistons operating therein, and means for trapping fluid by the piston in the smaller chamber for forming a cushion therein upon the completion of the stroke of the piston in one direction.

6. In a tool of the character set forth, the combination with a cylinder member having piston chambers of different diameters, of a piston having portions of different diameters respectively operating in the chambers, means for supplying motive fluid to both chambers and against the portions of the pistons operating therein, said means in cluding a passageway opening into the chamber of smaller diameter in advance of its outer end, and means between the passageway and said end and cooperatingwith the piston for trapping fluid behind said piston and forming a cushion for the piston upon the completion of its stroke.

7. In atool of the character set forth, the combination with a cylinder member having piston chambers of different diameters, of a piston having portions of diflferent diameters respectively operating in the chambers, and means for supplying motive fluid to both chambers and against the portions of the pistons operating therein, said means including a passageway opening into the chamber of smaller diameter in advance of its outer end, and said chamber of smaller diameter having a portion of its walls between the passageway and said portion snugly receiving the corresponding portion of the piston.

8. In a tool of the character set forth, the combination with a cylinder member having piston chambers of different diameters, of a piston having portions of diiferent diameters respectively operating in the chambers, a supply passageway opening into the smaller chamber contiguous to the larger chamber, means formed in the smaller por- &

tion of the piston for periodically affording 20 reciprocation of the piston, and a passage- Way leading from the larger chamber and opening into the smaller chamber in advance of the rear end thereof and in rear of the supply passageway, said chamber of smaller diameter having a portion in rear of the latter passageway arranged to snugly receive the smaller end of the piston to trap the fluid behind said portion and form a cushion.

In testimony whereof, I aflix my signature in the presence of two witnesses.

OMAR E. CLARK. Witnesses:

EDWD. L. OLDHAM, SULLIVAN V. JoHNsoN. 

